According to an internal Verizon document procured by Phandroid, the HTC Thunderbolt will be able to do simultaneous voice and data, though Verizon "cannot promise the experience will be one that is consistent with [their] brand." But how?

They won't be advertising the functionality, and the document asks Verizon peeps not to reference it to customers. But how's it even possible in the first place? We're not sure! Back in October, a WSJ article on the Verizon iPhone mentioned a forthcoming fix:

A solution that will allow CDMA networks to carry voice and data simultaneously will become commercially available in the first half of next year, said Brad Shewmake, spokesman for the CDMA Development Group, an industry organization.

So maybe it's that! Or maybe it's some 4G trickery, like the voice going over CDMA while the data transmits on LTE, or something like that. But in any event, even if your chipper Verizon salesperson won't mention it, rest easy knowing that you will probably be able to multitask on your Thunderbolt. It'll be your little secret. [Phandroid via Android Community via Slashgear]